- 4 teaspoons dry mustard powder
- 4 teaspoons water
- 1/2 teaspoon mirin
- 1 1/2 teaspoons low-sodium soy sauce
- 3/4 teaspoon sugar
- 1/4 cup canola oil
- 4 skinless, boneless chicken breast halves (about 6 ounces each)
- Salt and freshly ground pepper
- 1 head of bok choy or tat soi, or 2 bunches baby
- 1 tablespoon rice vinegar
- 1 bunch arugula
- Preheat the oven to 425°. In a bowl, stir the mustard with the water, mirin, 1 teaspoon of the soy and 1/2 teaspoon of the sugar.
- In an ovenproof skillet, heat 1 tablespoon of the oil. Season the chicken with salt and pepper and cook over high heat until golden, 2 minutes. Flip the chicken and brush with the mustard; transfer to the oven and roast for 8 minutes, or until cooked through. Transfer the chicken to a cutting board and let rest for 5 minutes; slice. Wipe out the skillet.
- Meanwhile, steam the bok choy or tat soi for 5 minutes. Drain; pat dry. In the same skillet, heat 1 tablespoon of the oil. Add the bok choy (or tat soi) cut side down and cook over high heat, turning once, until browned, 3 minutes. Transfer to a platter; season with salt and pepper. Arrange the chicken over the bok choy.
- In a bowl, whisk the vinegar with the remaining oil, soy sauce and sugar; season with salt and pepper. Add the arugula and toss; arrange over the chicken and serve.